<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<script>

var SVG_NS = "http://www.w3.org/2000/svg";

function boom()
{
  var svgElem = document.createElementNS(SVG_NS, "svg");
  var ellipse = document.createElementNS(SVG_NS, "ellipse");

  svgElem.setAttribute("viewBox", "0 0 30 40"); 
  document.body.appendChild(svgElem);
  document.body.appendChild(ellipse);
  ellipse.appendChild(svgElem);
  svgElem.removeAttribute("viewBox");
}

</script>
</head>

<body onload="boom()">

</body>

</html>

